Zirsinalite

zirsinalite

lomonosovite

lamprophyllite

lovozerite

Images

Formula: Na6CaZrSi6O18
Cyclosilicate (ring silicate), zirsinalite-lovozerite subgroup, lovozerite group, zirconium-bearing mineral
Crystal System: Trigonal
Specific gravity: 2.88 to 2.92 measured, 3.08 calculated
Hardness: 5½
Colour: Colourless, yellowish grey
Solubility: Rapidly corroded in air with the formation of a powdery coating of sodium carbonate. Slowly decomposed in cold dilute acids, readily decomposed at 60 to 80°C by 10% hydrochloric or sulphuric acid, with separation of gelatinous silica.
Common impurities: Ti,H2O
Environments

Pegmatites

Localities

At the type locality, the Koashva Open Pit, Koashva Mt, Khibiny Massif, Murmansk Oblast, Russia, zirsinalite occurs as rounded or irregular deposits up to 1 x 1.5 cm in size, colorless and transparent with a vitreous lustre. It was found at 180 m depth in a drill core on the eastern slope of Mt Koashva, in pegmatitic veinlets cutting alkalic rocks. It is associated with aegirine, lomonosovite and barium-bearing lamprophyllite, and replaced by lovozerite and by eudialyte. Zirsinalite is rapidly corroded in air with the formation of a powdery coating of sodium carbonate (AM 60.485-489).
Zirsinalite from the Khibiny Massif - Image

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